COSHH Cabinet Requirements: What the Law Actually Requires

What a COSHH Cabinet Has to Do

No regulation specifies a COSHH cabinet. What exists instead is a set of outcomes the store has to deliver, and a piece of HSE guidance that puts numbers on them.

For flammable liquids — the case where the specification actually bites — HSE's HSG51, Storage of flammable liquids in containers (third edition, 2015) sets out what a workroom cabinet or bin should be and hold:

Fire-resisting construction giving 30 minutes' integrity, with joints free from gaps and close-fitting doors
Spill retention of 110% of the volume of the largest vessel normally stored in it
No more than 50 litres of the more volatile flammable liquids, or 250 litres of higher-flashpoint ones, in a workroom
Fastenings with a melting point above 750 °C
Segregation from oxidisers, corrosives and energetic substances — not in the same cabinet

And one thing that is worth knowing before you spend: the enhanced cabinet standards a supplier may quote at you are, in HSE's own words, not a legal requirement in the UK.

This guide is about the store itself. For where to put it, what goes in it and how storage fits the rest of your controls, our COSHH cupboard and chemical storage guide is the parent article.

Where the Duty Comes From

Three provisions, none of which mentions a cabinet.

COSHH regulation 7(4)(a). Among the measures required to control exposure:

"arrangements for the safe handling, storage and transport of substances hazardous to health, and of waste containing such substances, at the workplace"

DSEAR regulation 6(6), for anything with a physical hazard classification:

"The employer shall arrange for the safe handling, storage and transport of dangerous substances and waste containing dangerous substances."

Health and Safety at Work etc. Act 1974, section 2(2)(b), which sits above both:

"arrangements for ensuring, so far as is reasonably practicable, safety and absence of risks to health in connection with the use, handling, storage and transport of articles and substances"

All three set an outcome and leave the method open. That is why there is no "COSHH cabinet standard" to comply with — and it is also why a cabinet on its own never discharges the duty. The arrangements do: what is held, how much, where, next to what, and who can open it.

Most solvents, thinners, fuels and aerosols fall under both COSHH and DSEAR, for different reasons. DSEAR and COSHH: which applies sets out how the two split.

The Quantity Limits — and Why They Are Not Limits

This is the part most often misquoted in both directions. HSG51 paragraph 211 gives the recommended maximum quantities for cabinets and bins:

"no more than 50 litres for extremely, highly flammable and those flammable liquids with a flashpoint below the maximum ambient temperature of the workroom/working area; no more than 250 litres for other flammable liquids with a higher flashpoint of up to 60 °C."

Then paragraph 212 does something guidance rarely does — it tells you the numbers are soft:

"These quantities are intended to be viewed as recommended maxima representing industry safe practice, rather than absolute limits."

There is explicit flexibility, because modern building layouts and open-plan workrooms can make the figures impractical. But the flexibility is conditional: where you propose to exceed the maxima, HSG51 says you "should consider recording your justification in your risk assessment", taking into account the properties of the materials, the size of the area and number of people in it, the quantities that could be spilled, ignition sources and fire spread, ventilation, the cabinet's fire-resisting performance, the arrangements for closing it in a fire, and the means of escape.

So the honest position is: 50 and 250 litres are the figures an inspector will expect you to have started from, and exceeding them is a decision you record rather than a breach you commit. Being able to point at that reasoning in your assessment is what separates the two.

One trap in the mixed-storage case. HSG51 says that for mixed storage "the worst-case situation should be applied, ie all materials in the storage cupboard or bin should be considered as being the same material as the one that has the lowest flashpoint". Put one tin of a low-flashpoint solvent in with 200 litres of higher-flashpoint product and the whole cabinet is assessed at 50 litres, not 250.

What "Fire-Resisting" Actually Means Here

Appendix 1 of HSG51 sets the performance requirements, and paragraph 214 is explicit that these "do not specify an absolute test or standard for the cupboard or bin itself, rather they relate to nominal construction principles":

The materials forming sides, top, bottom, doors and lid are "capable of providing the required fire resistance (ie 30 minutes' integrity) and reaction to fire (ie minimal risk)"
"the joints between the sides, top and bottom of cupboards and bins should be free from openings or gaps"
"the lid/doors should be close fitting against the frame of the bin/cupboard, such that there is a nominal overlap between the frame and lid/doors in their closed position"
"the supports and fastenings should be of a material with a melting point greater than 750 °C"

Paragraph 215 calls these "the minimum performance requirements for compliance with current legislation".

The standards question, answered plainly

HSG51 then names the more demanding specifications — BS EN 14470-1, Factory Mutual, Underwriters Laboratories, NFPA 30 — and says of them:

"Where standards go beyond the minimum requirements of UK health and safety legislation, it should be emphasised that their implementation in the UK is not a legal requirement."

It does add that for quantities above the recommended maxima, an enhanced-performance cabinet "can help them demonstrate that the measures they are taking are sufficient to reduce the risks so far as is reasonably practicable" — a genuine reason to buy one, in a specific circumstance.

And paragraph 217 puts the responsibility back where it belongs: "It is your responsibility to ensure that cabinets to any particular standard or design specification meet the minimum legal requirements." A certification mark is a claim about the product. It is not a finding about your workplace.

Spill Retention: 110% of the Largest Vessel

Paragraph 207 is the source of the figure everyone quotes:

"a limited quantity in suitable closed vessels may be stored in suitable cabinets or bins of fire-resisting construction that are designed to retain spills (capacity should be 110% volume of the largest vessel normally stored in it)"

Note largest vessel, not total contents. If the biggest container you normally keep in there is 20 litres, the sump needs to catch about 22 litres — regardless of how many smaller bottles sit alongside it.

The sump only works if it is empty. A sump full of rags, spare caps and dried product is a shelf, not a containment.

The Bit Cabinet Pages Leave Out: the Inside Is a Zone

HSG51 paragraph 208 makes an explicit DSEAR link that rarely appears on a product page:

"Under DSEAR you must determine the potential extent of the flammable atmosphere that could result from leaks and ensure all potential ignition sources are excluded from such areas... This requirement extends to cabinets, bins etc used to store lower flashpoint flammable liquids. For the storage of such flammable liquids, the whole of the inside of the cabinet, bin etc should normally be taken to be zone 2."

Zone 2 under DSEAR Schedule 2 means a place where an explosive atmosphere "is not likely to occur in normal operation but, if it does occur, will persist for a short period only". The practical consequence is small but real: nothing that could be an ignition source goes inside. No powered equipment, no chargers, no heaters, no lighting fitted into the cabinet.

Our guide to doing a DSEAR risk assessment covers how zoning works more generally.

Where the Cabinet Goes

Paragraph 209 is short and is the requirement most often broken by convenience. The cabinet should be in designated well-ventilated areas that are:

"away from the immediate processing area where possible; and do not jeopardise the means of escape from process and other areas."

A flammables cabinet in the corridor that everyone evacuates along is a worse arrangement than a slightly less convenient one, however good the cabinet is.

Segregation Inside the Store

Paragraph 210 is firm about mixed contents:

"The flammable liquids should be stored separately from other dangerous substances that may increase the risk of fire or compromise the integrity of the container or cabinet/bin, such as energetic substances, oxidizers and corrosive materials... it is still inappropriate to store these in the same cabinets or bins with other flammable liquids."

That holds even where the other substance is itself a flammable liquid or held in one. DSEAR regulation 6(4)(g) makes segregation of incompatible dangerous substances one of the seven priority control measures, and the SDS is where you find out what is incompatible with what — section 7 covers handling and storage, section 10 covers stability and reactivity. Our guide to reading a safety data sheet walks through both.

In practice, small businesses need two or three separate stores far more often than they need one expensive one: flammables in the fire-resisting cabinet, acids and alkalis apart from each other in a corrosive-resistant unit, oxidisers away from everything combustible.

Labelling the Containers, Not Just the Cabinet

A hazard sign on the door is useful. It is not the duty.

DSEAR regulation 10 requires that where containers and pipes used at work for dangerous substances are not already marked under the legislation in Schedule 5, the employer must ensure "the contents of those containers and pipes, together with the nature of those contents and any associated hazards, are clearly identifiable."

This is the decanting problem. A supplier's labelled 20-litre drum is fine. The unlabelled squeezy bottle someone filled from it is the failure — and it is the single most common storage finding in small workplaces. Our guide to COSHH hazard symbols covers what the pictograms mean if you are relabelling decanted containers.

Quick Checklist

Keeping the Store and the Paperwork in Step

The quantity question is the one that quietly drifts. A cabinet that was within the recommended maxima when it was assessed stops being within them when ordering habits change, and nothing prompts anyone to notice — the cabinet looks the same.

COSHHmate is being built so the register carries quantity and storage location alongside the classification, and the assessments that depend on them come round for review on a schedule rather than when someone remembers. Pricing will be a flat monthly fee with no per-user charges. If your storage arrangements and your paperwork have drifted apart, join the waitlist.

Sources

This is general guidance based on the published text of the COSHH Regulations 2002 and DSEAR 2002 — both of which extend to England, Wales and Scotland, with Northern Ireland covered by its own equivalent instruments — and on HSE guidance HSG51 (third edition, 2015). HSG51 covers containers up to 1000 litres; larger tanks and bulk storage are dealt with in separate HSE guidance. Not legal advice.